(under subclass 21.1) Subject matter wherein the working surface of the brush coincides with a surface of revolution generated by the rotation of a straight line about an axis parallel thereto, and wherein means are provided to move or to permit movement of the brush relative to its supporting structure and into engagement with the work during brushing.
(1) Note. The "working surface" of the brush is an imaginary brush-enveloping smooth surface defined by and encompassing all of the work-engaging end-points of the bristles of the brush.
